Manchester United have confirmed that a handful of his playing squad are suffering with a "virus".
Michael Carrick, Ryan Giggs and Paul Scholes were all left out of the travelling party that have recently landed in Romania ahead of tomorrow's Champions League encounter with CFR Cluj.
Discussing the omission of his midfield trio, Ferguson admitted that he had little choice but to leave them out.
"Carrick is in bed with a virus," Ferguson told reporters. "Giggs has a bit of a virus and felt rough so he was sent home.
"Scholes is at home because he wasn't feeling great this morning. He played so well on Saturday and at 37, I can't expect him to play again three days later."
Antonio Valencia will also miss the match with an ankle problem.